Mixing apparatus



Aug. 31, 1948. B. DE H. MILLER 2,448,042

MIXING APPARATUS Filad Sept. 14, 1943 v 4 Sheets-Sheet 1 INVENTOR B zweDe Haven Miller 7BY a.

ATTORNEYS Aug. 31, 1948. B. DE H. MILLER HIKING APPARATUS 4 Sheets-Sheet2 Filed 5691;; 14, 1943 l/ l 1/ I 1 I ll a TQWV A'ITORNEYS fl- 1948- B.DE H. MILLER 2,448,042

MIXING APPARATUS Filed Sept. 14, 1943 4 Sheets-Sheet 3 INVENTORBrzzpeDeHavenMlZer ATTORNEYS Aug. 31, 1948. B. DE H. MILLER 2,443,042

MIXING APPARATUS Filed Spt. 14, 1943 4 Sheets-Sheet 4 6 INVENTOR 5firaceflelfaaen M'Jkv' ATTORNEYS Patented Aug. 31, 1948 MIXING APPARATUSBruce De Haven Miller, Louisville, Ky., assignor to The GirdlerCorporation, Louisville, Ky., a

corporation of Delaware Application September 14, 1943, Serial No.502,272

- 1 This invention relates ,to the treatment of fluid, plastic, or otherflowable material in order to effect temperature exchange thereof, or toeffect a rapid, uniform and thorough dispersion of one or moreingredients in another ingredient where said ingredients are notmiscible, or at least not readily miscible, as in making an emulsion, orwhere chemical reaction between different ingredients is desired, but ata controlled rate, or where it is desired to remove heat of reactionsubstantially instantly after it is produced.

This invention is an improvement in mixing apparatus of the type inwhich the material being processed may be continuously passed through achamber and simultaneously mixed, agitated, emulsified, or otherwisetreated. The agitating mechanism is of the rotary type and theprocessing may be merely that resulting from the action of the agitatoror may also include temperature change, or maintenance, and/or theaddition of an ingredient to another ingredient or to a mix- 19 Claims.(Cl. 259-7) ture of ingredients at the desired point or points in thepath of flow through the processing chamber.

Apparatus embodying the invention may be employed in effectingnitration, alkylation, isomerization, or other chemical action inwhich'heat may be generated or absorbed, or for making emulsions such asmayonnaise, salad dressing, asphalt-water, paints, or the like, forincorporating a gas under pressure ina liquid, or for various otherpurposes.

The main object of the invention is to obtain effective, uniform andhigh speed mixing by means of a turbulent flow which facilitatesrapidheat transfer, maintains a substantially uniform temperature in spite ofrapid internal heat production, prevents, stratification and producesother desirable results. The turbulent flow includes an alternate highand much lower velocity of flow at different points in the zone aroundthe agitator, a tangential flow of high speed-material into slowermoving-material, a heating by impact elements and various othermovements and crosscurrents.

As an important feature of the invention, the agitator is rotatablysupported in a substantially cylindrical chamber with its axis paralleland eccentric with respect to the axis of the cylindrical processingchamber. Also, the agitator extends substantially the full length of theprocessing chamber, and is provided with beating or impact elementswhich are not only forced through the material but also tend to whirl itaround the agitator as said material flows longitudlnally through theprocessing zone, so that in passing through said zon the material flowscircumferentially along the peripheral wall of the chamber but atvarying velocities due to the wider chamber space at one side of theagitator than at the opposite one. The eccentricity prevents a annularstratification and any separating out of heavier ingredients due tocentrifugal force such as sometimes occurs when a concentricallydisposed agitator is employed. Preferably no scrapers are employed, asin some 08.568 scraper blades cause a bodily rotation of the material inthe chamber without thorough mixing. The agitator is operated at such aperipheral velocity that the flow of the material prevents films orlayers building up on the chamber wall and it has such form andarrangement and is rotated at such speed that a high degree ofturbulence is produced throughout the whole of the processing zone.

The eccentricity of the shaft in respect to the chamber wall is not sogreat as will cause the agitator .to act primarily on the material atone side only of the chamber, leaving that at th other side relativelyquiescent. The outside diameter of the agitator should be relativelylarge in respect to the inside diameter of the chamber and ordinarily isat least one-half of the inside diameter of the chamber. 7

The agitator preferably has a shaft which may be solid or hollow and hasbeating elements projecting from the periphery thereof. The shaft ispreferably comparatively large and its diameter should be at leastone-half the overall diameter of the agitaton' Also, the relativediameter and eccentric positioning of the agitator should be such thatthe outer periphery of the agitator encircles the axis of the processingchamber. The beater elements are thus comparatively short and may be ofvarious different types but are so.

designed, positioned and proportioned that they provide passagestherethrough or therebetween. Preferably they project into closeproximity to, but not into contact with, the peripheral wall at the sidetoward which the axis of the agitator is offset, so as to get themaximum of mixing with the minimum expenditure of motive power. With thepath of movement of the agitator close to the wall at one side, and withthe circumference of the agitator encircling the axis of the chamber, itwill be apparent that the overall diameter of the agitator should be atleast onehalf that of the chamber.

By this construction and arrangement the material will have a bodilyflow at a substantially higher mean velocity at one side of the agitatorthan at the other, and a different type and degree of turbulence will beproduced at the side of the agitator where the mean velocity of thematerial is the greatest and radial or tangential flow is substantiallyprevented, than at the opposite side of the agitator, where the meanvelocity of the body of the material is slower and the beater elementsmove the material not only around the agitator but also outward radiallyor tangentially 3 v by centrifugal force. In the thinner spaces the meanvelocity of the material is higher in spite of the greater surfacefriction on the peripheral wall, because of the greater tendency of thematerial to flow along with the beater or impact members and in the samegeneral direction. In the wider spaces there is a general tendency ofthe material to be thrown out tangentially into the slower moving bodyof material beyond the path of movement of said members. In the widerspaces the turbulence is the result of the different average peripheralspeeds of the material in, and that beyond, the path of movement of theheaters, the centrifugal effect on the material contacted by thebeaters, and the stirring action of the heaters.

In case it is desired that one or more of the fluids be admitted atspaced points in the path of flow in the processing chamber, thestructure, details, location, number and spacing of such points may bevaried through a comparatively wide range. The spaced inlets may be inthe peripheral wall, or in the agitator, or in a Figs. 2 and 3 aretransverse sections on the lines 2-! and 3-3 respectively, of Fig. 1;

Fig. 4 is a central longitudinal section through another form of theapparatus embodying further features of the invention and intermediateportions of the body being broken away;

Fig. 5 is a transverse section on the line 8-5 of Fig. 4, but on asmaller scale and viewed from the lower or drive end;

Figs. 6 and 7 are longitudinal sections on the lines 6-8 and 1-1 of Fig.5:

Fig. 7a is a transverse sectionsimilar to a portion of Fig. 5, butshowing an alternative construction;

Fig. 8 is an end viewof the lower end of the agitator, the shaftextension being shown in section; I

Fig. 9 is a development of an annular section of Fig. 8;

Fig. 10 is a central longitudinal section through a further form, anintermediate part being omitted, and

conduit in the chamber, and may be arranged in a row along the length ofthe chamber, or circumferentially thereof, or helically, or in scatteredpositions. They may be along substantially the entire length of thechamber or may be located near the inlet for the other fluid or fluids,or along the first part of the longitudinal flow through the chamber, ornear the main outlet, or along the last part of thepath of longitudinalflow. Such distribution may be decided upon in accordance with thecharacter of the ingredients going to make up the final mixture oremulsion, the reaction, if any, to be effected, and the results to beaccomplished. For instance, in some cases it may be desired tothoroughly, mix, emulsify, or chemically react two or more ingredients,before adding and mixing in a further ingredient. and in some cases alonger duration of mixing may be desired after all of the ingredientshave been admitted. Likewise, the number of the spaced points ofadmission of a final ingredient may be small or may include amultiplicity of very fine apertures.

As previously noted, the eccentric positioning of the agitator resultsin varying velocities of circumferential flow in the chamber. In somecases, where it is desired to add a final ingredient at a plurality ofspaced points, it is preferable to have these inlet points deliver tothe chamber where the velocity of flow in the chamber is the greatest,and in some cases it may be found preferable to have inlets where theturbulence of the flow in the chamber is the greatest..

The invention also involves various improvements in the details,construction, design and arrangement of different parts of the apparatusincluding seals for preventing leakage along the supports or drivingmeans for the agitator, shielding the bearings from any action by thefluids being processed, the agitator itself, the means for supplyingfluids to the chamber, and other features which will be noted inconnection with descriptions of several embodiments of the broaderinvention.

In the accompanying drawings there are illustrated several of the manypossible embodiments of the present invention.

In these drawings,

Fig. 1 is a central longitudinal section through a simple form ofapparatus embodying certain features of the invention, the centerportion being broken away;

Fig. 11 is a section similar to a portion of Fig. 10 but taken ina'plane at right angles thereto. In the construction shown in Figs. 1, 2and 3, there is provided a processing chamber having a cylindricalperipheral wall In and end walls Ii and i2, the end wall il having anoutlet it for the processed material and the end wall i2 having an inletIt for the material to be processed. The material, while being agitatedas hereinafter described, has a substantially uniform rate of continuousbodily flow longitudinally through the processing zone, in addition tothe annular and turbulent flow caused by the agitator. Thus successiveportions of the material will all remain in the chamber and be processedfor substantially the same length of time.

The inlet it may be connected to a supply pump drawing the material froma premixing tank or in controlled ratio from separate supply pipes forthe diflerent ingredients, or in some cases the end wall may be providedwith a plurality of inlets for the different ingredients and throughwhich such ingredients are delivered at controlled rates and incontrolled relative proportions by pumps or other forcing means. Theoutlet It, or a conduit connected thereto, may be provided withthrottling or flow controlling means. I

If it is desired to change the temperature. of the material as a part ofthe processing, or to maintain a given temperature if the processinginvolves an exothermic or endothermic reaction, or the development ofmechanical heat, or if the processing be primarily to rapidly heat orchill the material, there may be provided a jacket I! for a heattransfermedium. The annular space between the jacket and the wall l0 maybeprovided with an inlet It at one end and "an outlet I! at the oppositeend, which are shown as extending tangentially to said space. There maybe provided a helical baiile it between the inlet and the outlet whichwill prevent short circuit- 'ing of the heat transfer medium'from theinlet to the outlet .and cause it to flow in a helical path around theprocessing chamber. Suchbaffle is not required if the temperaturechanging medium bea volatile refrigerant such as ammonia, or a heatingmedium such as steam. 7

Within the processing chamber there is mounted an agitator having ashaft 20 with end extensions or stub shafts 2i and 22 Journalled in, on,or

outside of the opposite end walls. The shaft shown in Figs. 1 and 2 maybe solid, or may be '5 hollow and have end walls connected-to the shaftextensions 2| and 22 and supporting a cylindrical tube constituting theperipheral wall.

As shown, the stub shaft extension 2i is supported by a bushing23 in asocket 24 in the end wall ll, while the stub shaft 22 is mounted in aroller bearing 25 mounted on the end wall l2. The two bearings may bothbe of'either type and the character may be varied, depending upon thenature of the material being processed. The stub shaft 22 projectsbeyond the bearing 25 so that it may be connectedto any suitable sourceof power, such as an electric motor. To prevent leakage along the stubshaft 22 andthrough the into the processing chamber, and to prevent anyof the material being processed, which may leak past the seal, fromreaching the bearing25, these two parts are separated by a space 21 andprovided with openings 28, which may be in the form of radial grooves orchannels in the outer surface of the end wall l2. As shown, there arethree of these passages, and when the axis of the chamber is horizontal,one may be below the shaft and substantially vertical, while the'othe'rtwo are on.

opposite sides of the inlet I4. Thus a stream of water, steam, or othercleansing fluid, may be projected through either or both of the upperpassages 28 and flow around the portion of the shaft between the seal 25and the bearing 25 and drain out through the lower passage 28 As shown,the portion of the stub shaft 22 between the seal and the adjacentbearing is provided with circumferential grooves or ridges which tend toprevent flow of material along this portion of the stub shaft and aid inthe throwing oil. of material thereon, due to centrifugal action duringthe rotation of the agitator.

The stub shafts, bearings and seals may be of conventional form and maybe modified through a comparatively wide range.

As an important feature of the invention, the agitator and the bearingsthereof are eccentrically disposed in respect to the peripheral wall Inof the processing chamber, and the outside diameter of the agitator iscomparatively large in re spect to the inside diameter of the said wall.As illustrated, the outside diameter of the agitator is more thanone-half that of the chamber and the axis of the chamber is encircled bythe periphery of said agitator. As shown, the eccentricity is such thatthe radial distance from the periphery of the shaft to the chamber wallis cham benthe material is caused to swirl around the agitator by theimpact or action of the pins and-its velocity of circumferentialmovement will 'be substantially greater at one side of the chamber thanat the opposite side. This varying velocity in different sections of theannular chamber with agitation in both the section where the velocity isthe greatest and the section where the velocity is the lowest, producesextreme turbulence and greatly facilitates the thorough and uniformmixing of the ingredients of the mixture,

' of the annular chamber and are at some distance a bodily-one at highvelocity and with mixing or I stirring by movement of the pins throughthe material at a rate faster than that of the material. On the otherhand, in the regions where somewhere about twice as great at oneiside.as

the other and the diameter of the shaft is more than one-half theoverall diameter of the agitator.

The shaft 20 is provided with a plurality of beater elements which maycomprise pins'or projections 30 which are preferably radial and may be.cylindrical. The pins may be arranged in various difierent ways, but asillustrated, they are in a plurality of rows extending lengthwise of theflowing to the outlet I3 at the opposite end of the there is greaterclearance between the agitator and the chamber wall, the pins travel atthe same peripheral speed but the material is in greater volume and hasa lower mean velocity of bodily movement. As the ends of the pins orheaters are at some distance from the wall III in the region of maximumclearance between the agitator and the chamber wall there isconsiderable m'aterialbeyond the path of movement of the pins and eachpin tends to throw material out tangentially from its path into saidregion of maximum clearance. Thus, in the wider space the material ismixed by the stirring action of the pins, the centrifugal action on thematerial in the path of the pins, and eddying of the material which isbeyond the path of the pins. The alternate high velocity and lowervelocity and the resulting turbulence caused by the interaction of thedifferent types of flow result in an extremely effective and uniformmixing in a comparatively small apparatus and while there is a fairlyuniform rate of longitudinal flow of the turbulent mass from the inletto the outlet.

The apparatus parts are all simple in design, rigid in construction, andreadily taken apart for cleaning. Any suitable source of power may beemployed and connected to the shaft 22 for rotating the agitator. Thespeed of rotation will vary with the character of the material treatedas well as the shape and relative proportions of the various parts. Ithas been found that with a peripheral speed of at least 300 ft. perminute, the desired results may be obtained. As an example, the chambermay have an internal diameter of 24 inches and the agitator an outsidediameter of 1'7 inches. A rotation of the agitator at 400 R. P. M. willgive a peripheral speed of about 30 ft. per second for the outer ends ofthe pins. The speed should not be so great as would create a vacuumadjacent to the shaft or in the rear of the beater members, but whetheror not such a vacuum might be produced would depend to some extent uponthe pressure employed in the processing chamber. Where volatileingradients are employed, the pressure may be high enough to prevent anyvolatilization within the chamber. On the other hand in some cases itmay be desired to deaerate or remove volatile constituents whileagitating, mixing or processing, and in such cases the chamber may beoperated under vacuum.

In Figs. 4 to 9 inclusive, 9. further form of apparatus is illustratedand additional novel features are incorporated, which are not shown inFigs, 1, 2 and 3. In Fig. 4 there are shown the top, bottom, and amiddle section or the apparatus. The portions between the middle sectionand the top and bottom sections are omitted to indicate that the chambermay be 01' any desired length in respect to the diameter and otherproportions shown in Fig. 4. In this iorm, the apparatus is so arrangedthat the axis of the shaft and the processing chamber are verticalrather than horizontal and means are provided for the admission of oneor more fluids to the chamber in which the material is being processed,and means are provided for protecting the seal and bearings 01 theagltator in case any of the ingredients employed in making the mixtureor emulsion are of acidic or other character which may adversely affecta bearing or seal. In the construction illustrated, the processingchamber is formed of a vertically disposed cylinder 35 with top andbottom heads 35 and 31. Surrounding the peripheral wall of the chamberis a jacket 86 providing an annular space for refrigerant or othertemperature changing medium. The jacket 35 has annular headers 35 and40, which in turn have outlet and inlet connections 4! and 42 for thetemperature changing medium, which may be hot water, steam, brine,liquid ammonia, freon. or the like. If such medium be volatilized in thejacket the liquid level thereof may be maintained in any manner wellknown in the art, ii, that be desirable.

The agitator is of the same general type as that hereinbefore describedand includes a comparatively large eccentrically mounted shaft 43 havingpins 44 projecting therefrom. The relation between the sizes of theshaft and chamber,

the degree of eccentricity and the spacing between the ends of the pinsand the peripheral wall at the wide and narrow sections may be about thesame as shown in Figs. 1 and 2.

The upper end of the agitator has a stub shatt 45 which is mounted in abearing 45 in the head 36, and the head has an annular flange 41projecting into a socket 52 in the end of the agitator shaft 48 andserving to support a rotary seal including a carbon ring 45, a steelring 49, and a neoprene ring 50, pressed down by a spring engaging theinner race ring of the bearing 46. The socket 52 into which the flange41 extends,

and which carries the seal, communicates at its upper end with the upperend 01' the processing chamber through a passage 54, so that thematerials being processed cannot come in contact with either the rotaryseal or the bearing. If g it will break along a fine line of cleavagewhen the rotation of the agitator begins.

The agitator, at its lower end, has a shaft extension 56, to whichsuitable driving means may be connected. The shaft extension may bemounted in a bearing 51, and between this bearing and the processingchamber there is provided a seal which will prevent the contact of anyof the ingredients of the material being processed, with said bearing.This seal is disposed in a chamber 55 and is shown as including a pairof conical neoprene washers 56 pressed in opposite directions by aspring 66 into conical sockets in carbon rings 6|. Lubricant may bedelivered under pressure to this chamber through a passage 52 in thehead 31 and lubricant may be delivered under pressure to the bearing 51through a nipple or oil cup 55.

The main ingredient, or main portion of a premix oi some-oi theingredients, may be delivered through a passage 64 in the head 51 andenter the processing chamber at the bottom of the latter. After beingprocessed the product may be delivered through an outlet 65 at theopposite end. It the material delivered through the inlet 54 be acidicor of other character which might adversely afiect the bearing 51 or theseal, another ingredient oi the desired mixture may be delivered througha supply passage 51 shown in dotted lines to an annular passage 66formed around the shaft above the seal. This passage 56 may be disposedwithin and above a collar 65 projecting into a cavity in the end of. theshaft. The passage 55 is of substantially conical form, and its topportion is relatively restricted, so that it serves as a trap to preventingredients which might enter through the inlet 54, from contacting theseal or bearing. The center portion or I the passage is of substantiallyhigher elevation than the periphery, so that the lip or flange 66 iormsan annular dam or wall.

If desired, some small quantity of the fluid delivered to the passage 66from inlet 61 may continuously flow directly into the lowermost portionof the processing chamber countercurrent to any possible flow toward theseal from the processing chamber. As the trap is an inverted one, itwill be seen that if the fluid delivered through passage 61 be oflighter speciflc gravity than that delivered through inlet 64, theheavier liquid cannot flow up over the annular ridge or dam 69 in thetrap and get to theseal or bearing. During operation, sufllcientpressure is maintained on the fluid introduced through passage 66 tomaintain a body of this fluid over the barrier or dam 69. On stoppingthe operation and draining the chamber, the main inlet will be opened,but during the draining the contents of the chamber cannot flow intocontact with the seal because the passage within the collar 68 ismaintained full of the lighter hydrocarbon liquid, by means of checkvalve in the feed line to passage 66, or other suitable means capable ofpreventing the liquid from flowing back out of that passage when thefeed pressure is relieved.

The body of the agitator shaft has a plurality of passages 10 extendinglengthwise thereof from the trap or chamber 66 and closely adjacent tothe peripheral surface and communicating with the processing chamberthrough comparatively small ports 1| at their upper ends. These passagesmay be of various different lengths and arranged in any desired order soas to deliver fluid from the passage 51 to the processing chamber atpoints which are not only spaced lengthwise of the chamber but alsocircumferentially thereof so that the fluid delivered through passage 61may be one of the ingredients being processed. In Fig. 9 there is shownan annular development of a section through the various passages Illshown in Fig. 8. In this particular form it will be noted that thepassages are eight in number and i divided into two groups so that thefirst and fifth are the longest, are diametrically opposite to eachother, and deliver to the chamber at points farthest from the main inlet84'. The second and sixth are somewhat shorter; the third and seventhare still shorter, while the fourth and eighth. which are alsodiametrically opposite to each other, terminate at only a short distancefrom the passage 66.

Thus, as the agitator is rotated at relatively high speed. theingredient delivered through the passage 61 will enter the processingchamber at four different levels and at diametrically opposite sides ofthe main shaft at each of said levels. As the shaft is rotated, theliquid will be thrown by centrifugal force as jets into the otheringredients being agitated by the impact members 44 and being cooled bythe jacket. This fluid may be delivered under pressure so as to formsaid jets. This is merely illustrative of one way in which an ingredientmay be delivered to the chamber in quantities which are relatively smallin respect to the main body of material in the chamber and at aplurality of spaced points, for mixing with or reacting with aningredient or mixture of ingredients delivered through the inlet B4.

In this form of apparatus there is shown another means for delivering aningredient to the processing chamber at spaced points along the lengththereof and inwardly through the peripheral wall. This maybeincorporated in an apparatus which has or does not have the passages 10and ports II above referred to., A plate is shown as welded to the outersurface of the wall 35 along the length thereof and extending through aslot in the outer wall 38 of the jacket for the temperature controllingmedium. This plate and the wall 35 have passages 16 therethrough and theouter ends of these passages are connected to conduits 11 which may beconnected to a source of supply for a fluid, or to different sources ofsupply for a plurality of fluids, to be delivered to the processingchamber along the length. or part of the length, thereof. The separatetubes Il may have individual va ves so that the fluid may be deliveredat difierent rates in different port ons of the length of the chamber,or the ports 16 may be of different sizes.

Instead of providing a plate 15, there may be provided a plurality ofcollars or plugs through which the passages 18 extend. The plate 15, ineffect, forms a partition in the jacket but this is immaterial, as thelower end of the plate preferably terminates above the header 40 so thatthe temperature changing medium may readily flow upwardly on oppositesides of the plate and there is no need for its circumferential flow.

In Fig. 7a is shown a conduit Ila disposed in and extending lengthwiseof the temperature controlling jacket, and communicating with all of theports 16. The same constuction shown in Figs. 7 or 7a maybe duplicatedat the opposite side of the chamber if it is desired to introduce afurther ingredient or separate portion of the same ingredients onopposite sides.

' l0 ber, and in order to obtain this result, it is necessary to varythe relative rates of flow of the ingredients. the flow or pressure ofthe temperature connections 80 at their outer ends for temperaturerecording instruments.

The apparatus may be employed for conducting processes at a temperaturevery substantially above or very substantially below atmospherictemperature, and in that case the Jacket 38 is encased in a thick layerof insulation 8|.

- As will be noted from Figsmi and 9, the passages 10 extend along onlya comparatively short portion of the length of the agitator shaft sothat all of the fluid introduced through the passage 68 will enter theprocessing chamber in the lower part thereof. The passages I6 may bedistributed along the full length of the chamber, but as indicated inFig. 4, the plate 15 terminates only shortly beyond the middle of thechamber so that all of the additional material delivered through tubes"or Ila will enter at spaced points along the lower half of the chamber.Thus, the upper half will serve for the further intermixing oremulsifying of ingredients already admitted to the chamber, or forholding the temperature for some time after a reaction has taken placeor while it continues. is not necessary that'the thermo-couple wellsextend along a greater section than do the inlets 16, as they are forindicating the temperature where reaction and/or main mixing may betaking place, so that proper control may be effected, but it will ofcourse be evident that the thermocouple wells may extend along the fulllength to permit one to ascertain if further temperature change takesplace beyond the upper port 16, or the thermo-couples may be entirelyomitted, particularly if temperature change in the material isimmaterial or does not take place.

From Fig. 5 it will be seen that the-inlets 16 It is important in someappartus to maintain an I from the plane in which the axis of theagitator is offset from the axis of the chamber. If the shaft be rotatedclockwise, as viewed from the drive end, and as indicated in Fig. 5, thematerial in the chamber will be traveling at its highest speed at theleft of the agitator, as viewed in Fig. 5, and the material deliveredthrough the inlets I6 will be drawn directly into the part of thechamber where the velocity is the greatest and the layer of materialagainst the peripheral wall is the thinnest. On the other hand, if theshaft of the agitator be rotated counterclock-' wise, the addedingredient will join the stream where a portion will be projectedtangentially into the space where the turbulence is due in part to thecentrifugal action of the beater elements on the material in the paththereof and the throwing of material out into the layer beyond the pathof movement of said elements. In either case the fluid entering theinlets I6 and/ or II will be swept in a tangential direction by the highspeed annular movement of the mass in the chamber. For some types ofmaterials it may be found best to rotate the agitator counterclockwise,and

. for other types of materials it may be found best to rotate itclockwise or to place the inlets at Ordinarily it some other positions.The material delivered through inlets I8 may be under high pressure soas to form high velocity jets, aiding in the mixing action.

The construction shown in Figs. 10 and 11 is similar in many respects tothat shown in Figs. 4 and 5 but differs in many details and particularlyas to the position and arrangement of the inlets for the addedingredients and the character of the seals. The construction includes aprocessing chamber having a peripheral wall 83 surrounded-by a jacket 84providing a space for the temperature controlling medium, and outside ofthis a layer of insulation 88. The bottom and top walls 88 and 81support the shaft extensions 89 and 88 of the agitator shaft, whichlatter may be hollow with a peripheral wall 88 and end walls 9| and 92.The peripheral wall is provided with radially extending pins. 88 servingas impact or beater elements.

The main ingredient or ingredients may be delivered through an inlet 94in the bottom wall and the product may pass out through an outlet 98 inthe top wall. The added ingredient may be delivered through a pipe 98extending lengthwise of the processing chamber and beyond the path ofmovement of the agitator and preferably adjacent to the peripheral wall83. This may extend through the top wall and connect to a suitablesource of supply and its lower end may be held in position by a closureplug 91 extending into a socket in the bottom wall. The pipe may have aseries of very small apertures 98 arranged in a row lengthwise of thepipe and these apertures may be only in the lower section of the pipe oralong the entire length ofthe pipe or only at the upper section,depending upon the particular process to be carried out and theingredients employed. Although apertures 98 may face the agitator, theypreferably face in a tangential direction so that the fluids deliveredthrough said apertures will enter the turbulent stream and any heat ofreaction between the fluids will be almost instantly removed as theturbulent stream is forced against the wall 83, which serves as a heattransfer wall if the jacket 84 be provided and if a cooling medium bedelivered to it.

As previously noted, Fig. 11 is a section at right angles to the planeof Fig. 10 and shows that diametrically opposite to the inlet pipe 98there may be provided a tube 99 mounted in the same way but havingthermo-couples I88 along the length thereof so that the temperatureofthe material at any point along the length of the processing chamber maybe determined. The inlet pipe 98 and the'thermocouple'tube 99 arepreferably arranged midway between the portion of the processing chamberof greatest radial dimension and the portion of minimum radialdimension.

The upper end wall 81 may have adetachable plate I8I which carries abearing and seal and the lower end wall 88 may have'a somewhat similarplate I82 likewise carrying a seal and a shaft bearing. These may bothbe somewhat similar to that shown at the lower end of Fig. 4 and adetailed description thereof would seem to be unnecessary, other than asto certain details.

There may be provided a passage I88 through which mercury or othersuitable sealing liquid may be delivered under pressure so as to form afurther seal in an annular groove I84 above the main seal. Instead ofdelivering added ingredient to the chamber through longitudinallyextending passages in the rotor, as shown in Fig. 9,

12 such added ingredient may be delivered through a passage I to anannular groove I88 above the groove I 84 to which mercury is supplied.The plate I82 is shown as provided with an annular flange I81 internallyand externally tapered and spaced from the under surface of the lowerend wall 8| of the a itator so as inform a seal and an annular passageI88 which may receive added ingredient from the annular groove I86; Thisannular passage I88 may be provided with radial passages I88 fordischarging, into the processing chamber, added ingredient deliveredthrough the passage I88. The outlets of the separate passages I88 mayall be at the same distance from the end of the agitator or they may beat different angles so as to deliver at different elevations. The endsof these passages may be wholly or pargially closed by plugs to controlthe flow of the ets.

At the top the flange II8 around the seal and which extends into a cupIII may have its surface roughened and the space between the opposedsurfaces may be filled with parailln or wax or other material which maybe poured in hot and set up to form a seal which will break but leave noappreciable clearance when rotation of the shaft starts. The materialshould be one insolu-v ble in or immiscible with the fluids beingprocessed.

It will be obvious that various details of the construction may bevaried through comparatively wide limits depending upon the character ofthe fluids to be processed, the temperature and pressure to bemaintained, and various other factors.

Various new and important processes may be carried out in the variousforms of the apparatus illustrated and certain of such processes areclaimed in companion applications, but in the present application onlythe apparatus is being claimed.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A mixing apparatus having a substantially cylindrical elongatedchamber having a peripheral wall presenting a substantially smooth innersurface, said chamber being provided with an inlet and an outlet for thecontinuous flow of a fluid generally lengthwise therethrough, a jacketencircling said chamber and having an inlet and an outlet for a heatexchange medium, and an agitator within said chamber and including ashaft of a diameter equal to substantially onehalf that of the chamber,and having its axis eccentrically positioned in said chamber to anamount not to exceed the radius of said shaft, and provided with beaterelements spaced apart along the length thereof and offering relativelysmall resistance to said'through flow, whereby the circumferential flowof the fluid in said chamber is substantially greater at one side ofsaid agitator than at the opposite side and stratification of said fluidadjacent to said jacket is prevented.

2. An apparatus for continuously processing flowable material, includingan elongated chamber having a substantially cylindrical peripheral wallwith a substantially smooth inner surface, the length of said chamberbeing at least as great as the diameter thereof, an inlet at one end andan outlet at the other end to permit the flow of a material generallylengthwise through said chamber, and an elongated agitator within saidchamber and having a shaft and beater memthrough flow, the overalldiameter of the agita tor being at least one-half the diameter of saidchamber, the diameter of the shaft being at least one-half the overalldiameter of the agitator, said shaft being disposed parallel to andeccentric with respect to the axis of the chamber, thus pro-' viding aregion of maximum clearance between.

14 5. An apparatus for continuously processing ilowable'material,including an elongated chamber having a substantially cylindricalperipheral the shaft and the chamber wall at one side, and. v

a region of minimum clearance at the diametrically opposite side of saidshaft, the extent of said eccentricity being such that said beatermembers are closely adjacent to said wall in the region of minimumclearance, and whereby the material being treated is forced at highvelocity between said wall and said shaft in the region of minimumclearance and has a turbulent flow in the region of maximum clearance, apart of said flow being between the beater members on the"- shaft, and apart being between the path of movement of the beater members and saidwall in the region of maximum clearance.

3; An apparatus for continuously processing flowable material, includinganelongated chamber having a substantially cylindrical peripheral wallwith a substantially smooth inner surface.

the length of said chamber being at least as great as the diameterthereof, an inlet at one end and an outlet at the other end to permitthe flow of a. material generally len thwise through: said chamber, andan elongated agitator within said chamber and having a shaft and beatermembers secured to said shaft along the length thereof and around theperiphery thereof, and spaced apart to offer relatively small resistanceto said through flow, the overall diameter of the agitator being atleast one-half the diameter of said chamber, the diameter of the shaftbeing at least one-half the overall diameter of the agitator. said shaftbeing disposed parallel to and eccentric with respect to the axis of thechamber, thus providing a region of maximum clearance between the shaftand the chamber wall at one side, and a region of minimum clearance atthe diametrically opposite side of said shaft, the extent of saideccentricity being such that said beater members are closely adjacent tosaid wall in the region of minimum clearance, and extend approximatelyone-half of the distance to said wall in the region of maximumclearance.

4. An apparatus for continuously processing fl owable material, incuding an elongated chamber having a substantially cylindrical peripheralwall with a substantially smooth inner surface, the length of saidchamber being at least as great as the diameter thereof, an inlet at oneend and an outlet at the other end to permit the flow of a materialgenerally lengthwise through said chamber, and an elongated agitatorwithin said chamber and having a shaft and beater members rigidlysecured to said shaft, the overall diameter of the agitator being atleast one-half the diameter of said chamber, the diameter of the shaftbeing at least one-half the overall diameter of the agitator, said shaftbeing eccentrically dis-'- posed with respect to the axis of thechamber, thus providing a region of maximum clearance between the shaftand the chamber wall at one side, and a region of minimum clearance atthe diametrically opposite side of said shaft, the extent of saideccentricity being, such that said heater members come closely adjacentto said wall in the region of minimum clearance.

wall with a substantially smooth inner surface, the length of saidchamber being at least as great as the diameter thereof, an inlet at oneend and an outlet at the other end for the flow of fluid generallylengthwise through said chamber, and an elongated agitator eccentricallydisposed within said chamber and having a shaft and beater membersprojecting therefrom along the length thereof and around the peripherythereof, extending substantially radially from the shaft, and

of a length substantially'less than the diameter s of'the shaft, theoverall diameter of the agitator 7 being at least one-half the diameterof said chamber, to provide a region of maximum clearance between theshaft and the chamber wall at one side, progressively merging into aregion of minimum clearance at the diametrically opposite side of saidshaft.

6. An apparatus for continuously processing flowable materials,including a, vertically disposed substantially cylindrical chamberhaving top and bottom end walls: a rotatable agitator in said chamberwith its axis eccentrically disposed in respect to the axis of saidchamber, and having a shaft extending through said bottom wall, abearing encircling said shaft outside of said chamber, said agitatorhaving an annular recess in its lower end presenting an outwardly anddownwardly inclined upper surface, and said bottom wall having anannular flange projecting into said recess, means for delivering oneingredient to the chamber at one side of said shaft, and means fordelivering a second ingredient to said annular recess, whereby saidbearing is protected from contact with said first mentioned ingredient.

'7. An apparatus for continuously processing ,ilowable materials,including a vertically disposed substantially cylindrical chamber havingtop and bottom end walls, a rotatable agitator in said chamber andhaving a shaft extending through said bottom wall, a bearing encirclingsaid shaft outside of said chamber, said agitatorhaving an annularrecess in its lower and presenting an outwardly and downwardly inclinedupper surface, and said bottom wall having an annular flange projectinginto said recess, means for delivering an acidic ingredient to thechamber at one side of said shaft, and means for delivering a lighteringredient to said annular recess, whereby said bearing is protectedfrom contact with the said first mentioned ingredient, and wherebyrotation of said agitator tends to cause flow of material from saidflange into said chamber by the action of centrifugal force.

-8. A mixing apparatus having a chamber provided with a substantiallycylindrical peripheral wall, an inlet at one end of said chamber and anoutlet at the opposite end, an agitator having its axis eccentricallypositioned in respect to the axis of said chamber and having beaterelements whereby the circumferential flow of the fluid in said chamberby the action of said heater elements is substantially greater at oneside of said agitator than at the opposite side, and means forprojecting a second fluid into said chambersaid shaft and disposedapproximately midway between the minimum and maximum radii of thechamber in respect to the axisof the shaft, and having a plurality ofopenings along the length thereof and directed substantiallytangentially of said agitator.

10. A mixing apparatus including a substantially cylindrical chamber, arotatable agitator therein and having its axis eccentrically disposed inrespect to the peripheral wall of said chamber, whereby circumferentialflow in said chamber is at higher velocity at one side of the agitatorthan at the other, and means for delivering a fluid to said chamber atspaced points along the length thereof and in the direction of flow ofthe contents of said chamber around said agitator.

11. A mixing apparatus including a substantially cylindrical chamberhaving an inlet at one end and an outlet at the other, an agitatorhaving a shaft eccentrically disposed in said chamber, a delivery pipein said chamber substantially parallel to said shaft and disposedapproximately midway between the minimum and maximum radii of thechamber in respect to the axis of the shaft, and having a plurality ofopenings along the lengthy thereof and delivering in the direction ofrotation of saidagitator.

12. A mixing apparatus including a vertically disposed substantiallycylindrical chamber, an} agitator therein and having a verticallydisposed shaft, a bearing forthe lower end of said shaft, an inlet-forsaid chamber for one ingredient to be processed,'a trap at the lower endof said chamber encircling said shaft, and means for delivering a secondingredient to be processed to said trap, said agitator having aplurality of delivery passages .leading from said trap to said chamber.

13. A mixing apparatus including a vertically 16 spaced points in saidchamber along the length thereof.

16. A mixing apparatus including a chamber having a rotatable agitatortherein and provided with a shaft extending to the exterior of saidchamber, a bearing for said shaft, a seal around said shaft and betweensaid bearing and the interior of said chamber, a liquid trap above saidseal, means for delivering liquid to said seal, and means fordistributing liquid from said seal to spaced points in said chamberaround the circumference of said agitator.

17. A mixing apparatus including a chamber having a rotatable agitatortherein and provided with a vertically disposed shaft extending to theexterior of said chamber, a bearing for the lower end of said shaft, aseal around said shaft and between said bearing and the interior. ofsaid chamber. a liquid trap above said seal and having an inlet and anoutlet, and means for delivering liquid to said seal, said trapencircling said shaft and having an annular upwardly extending wallterminating above the inlet and the outlet from said trap.

disposed substantially cylindrical chamber, an

agitator therein and having a vertically disposed shaft eccentricallydisposed in respect to the peripheral wall of said chamber, a bearingfor the lower end of said shaft, an inlet to said chamber for oneingredient to be processed, a trap at the lower end of said chamberencircling said shaft, means for delivering a second ingredient to beprocessed to said trap and thence to said chamber to thereby preventpassage of said first mentioned ingredient to said bearing, and meansfor delivering a fluid to said chamber at spaced points along the lengththereof and in a direction substantially tangential to said agitator.

14. A mixing apparatus including a chamber having a rotatable agitatortherein and provided with a shaft extending to the exterior of saidchamber, a bearing for said shaft, a seal around said shaft and betweensaid bearing and the interior of said chamber, a liquid trap above saidseal, means for delivering liquid to said seal, and means fordistributing liquid from said seal to spaced points in said chamber.

15. A mixing apparatus including a chamber having a rotatable agitatortherein and provided with a shaft extending to the exterior of saidchamber, a bearing for said shaft, a seal around said shaft and betweensaid bearing and the in-' terior of said chamber, a liquid trap abovesaid 18. A mixing apparatus including a chamber having a verticallydisposed rotatable agitator shaft extending to the exterior of saidchamber, a bearing for the upper end of said shaft, a seal below saidbearing and a trap around said shaft and below said seal, said trapcomprising a cupshaped recess for retaining liquid and communicatingwith the interior of said chamber only above said seal.

19. A mixing apparatus including a chamber having a rotatable agitatortherein and provided with a shaft extending to the exterior of saidchamber, a bearing for the upper end of said shaft, a seal below saidbearing and a trap around said shaft, below said seal and communicating.

with the interior of said chamber only above said seal, said trapcontaining a fiowable material preventing the material being processedfrom contacting with said seal.-

BRUCE DE HAVEN MILLER.

' REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 7 38,915 Rowan June 16, 1863104,304 Harris June 14, 1870 212,453 Fort et al Feb. 18, 1879 246,992Anderson Sept. 13, 1881 1,340,464 Sehaub May 18, 1920 1,487,208 Cooke eta1 Mar. 18, 1924 1,500,845 'Plauson July 8, 1924 1,751,922 Joseph Mar,25, 1930 1,832,148 Spoerri Nov.'17, 1930 2,083,171 Nester June 8, 19372,148,608 De Stubner Feb. 28, 1939 2,217,318 Nanna Oct. 8, 19402,268,905 Sehaub et al Jan. 8, 1942 2,282,866 Hagen May 12, 1942 FOREIGNPATENTS Number Country Date 331,877 Italy Nov. 18, 1935 507,519 GermanyOct. 3, 1920 564,068 Germany Nov. 12, 1932 728,812 France July 12, 1932

